MEDIUM
7th ICSE
IMPORTANT
Earn 100

Explain the term sublimation? Is sublimation of naphthalene a physical or a chemical change. Give reason.

Important Questions on Physical & Chemical Changes

MEDIUM
7th ICSE
IMPORTANT
Simplified Chemistry>Chapter 2 - Physical & Chemical Changes>EXERCISE>Q 8
Ammonium chloride is also a sublimable solid. Give a reason why sublimation of ammonium chloride involves a physical and a chemical change.
MEDIUM
7th ICSE
IMPORTANT
Simplified Chemistry>Chapter 2 - Physical & Chemical Changes>EXERCISE>Q 9
State why addition of sodium chloride to water is considered a physical change, while addition of dilute sulphuric acid to zinc is considered a chemical change.
MEDIUM
7th ICSE
IMPORTANT
Simplified Chemistry>Chapter 2 - Physical & Chemical Changes>EXERCISE>Q 10
Photosynthesis is a natural process by which green plants manufacture food in the presence of sunlight.
Are any new products formed during the above process. (Yes / No)
MEDIUM
7th ICSE
IMPORTANT
Simplified Chemistry>Chapter 2 - Physical & Chemical Changes>EXERCISE>Q 10
Photosynthesis is a natural process by which green plants manufacture food in the presence of sunlight.
Can the change be reversed or is it irreversible?
MEDIUM
7th ICSE
IMPORTANT
Simplified Chemistry>Chapter 2 - Physical & Chemical Changes>EXERCISE>Q 10
Photosynthesis is a natural process by which green plants manufacture food in the presence of sunlight.
State the conclusions which can be drawn, to represent photosynthesis as a physical or a chemical change.
HARD
7th ICSE
IMPORTANT
Simplified Chemistry>Chapter 2 - Physical & Chemical Changes>EXERCISE>Q 11
Give reasons why- separation of mixture e.g. iron from a mixture of iron & sulphur is a physical change, but heating a mixture of iron & sulphur is considered a chemical change.
MEDIUM
7th ICSE
IMPORTANT
Simplified Chemistry>Chapter 2 - Physical & Chemical Changes>EXERCISE>Q 12
Explain in brief the involvement of energy in physical & chemical changes.
EASY
7th ICSE
IMPORTANT
Simplified Chemistry>Chapter 2 - Physical & Chemical Changes>OBJECTIVE TYPE QUESTIONS>Q 2
Desirable changes are meaningful, while undesirable changes are unfavourable.